Neuron-like differentiation of bone marrow-derived mesenchymal stem cells

ETVs dictate hPSC differentiation by tuning biophysical properties

Stem cells maintain a dynamic dialog with their niche, integrating biochemical and biophysical cues to modulate cellular behavior. Yet, the transcriptional networks that regulate cellular biophysical properties remain poorly defined. Here, we leverage human pluripotent stem cells (hPSCs) and two morphogenesis models - gastruloids and pancreatic differentiation - to establish ETV transcription factors as critical regulators of biophysical parameters and lineage commitment. Genetic ablation of ETV1 or ETV1/ETV4/ETV5 in hPSCs enhances cell-cell and cell-ECM adhesion, leading to aberrant multilineage differentiation including disrupted germ-layer organization, ectoderm loss, and extraembryonic cell overgrowth in gastruloids. Furthermore, ETV1 loss abolishes pancreatic progenitor formation. Single-cell RNA sequencing and follow-up assays reveal dysregulated mechanotransduction via the PI3K/AKT signaling. Our findings highlight the importance of transcriptional control over cell biophysical properties and suggest that manipulating these properties may improve in vitro cell and tissue engineering strategies.

Mesenchymal stem cells and their extracellular vesicle therapy for neurological disorders: traumatic brain injury and beyond

Traumatic brain injury (TBI) is a complex condition involving mechanisms that lead to brain dysfunction and nerve damage, resulting in significant morbidity and mortality globally. Affecting ~50 million people annually, TBI's impact includes a high death rate, exceeding that of heart disease and cancer. Complications arising from TBI encompass concussion, cerebral hemorrhage, tumors, encephalitis, delayed apoptosis, and necrosis. Current treatment methods, such as pharmacotherapy with dihydropyridines, high-pressure oxygen therapy, behavioral therapy, and non-invasive brain stimulation, have shown limited efficacy. A comprehensive understanding of vascular components is essential for developing new treatments to improve blood vessel-related brain damage. Recently, mesenchymal stem cells (MSCs) have shown promising results in repairing and mitigating brain damage. Studies indicate that MSCs can promote neurogenesis and angiogenesis through various mechanisms, including releasing bioactive molecules and extracellular vesicles (EVs), which help reduce neuroinflammation. In research, the distinctive characteristics of MSCs have positioned them as highly desirable cell sources. Extensive investigations have been conducted on the regulatory properties of MSCs and their manipulation, tagging, and transportation techniques for brain-related applications. This review explores the progress and prospects of MSC therapy in TBI, focusing on mechanisms of action, therapeutic benefits, and the challenges and potential limitations of using MSCs in treating neurological disorders.

Exosomal miR-590-3p derived from bone marrow mesenchymal stem cells promotes osteoblast differentiation and osteogenesis by targeting TGFBR1

Bone marrow mesenchymal stem cells (BMSCs) have been verified to be essential factors regulating osteogenic functions, which is mainly attributed to their secretion of extracellular vesicles. Exosomes derived from BMSCs (BMSCs-Exo) contribute to osteoblast functions that are critical for improving bone defect. Our current study aims to investigate the molecular mechanism dominated by BMSCs-Exo that affects osteoblast differentiation and osteogenesis. The first step this study validated that BMSCs co-culture enhanced the differentiation ability of osteoblast and promoted bone mineralization, while these tendencies were abolished after GW4869 treatment. Next, the BMSCs-Exo was isolated and identified by TEM observation, insight detection, and western blot analysis. Furthermore, BMSCs-Exo treatment could efficiently promote the differentiation ability and the bone mineralization of osteoblasts, decrease the mRNA levels of Collagen I and Collagen III, and increase the levels of osteogenic proteins, including alkaline phosphatase (ALP), Turning Bone Morphogenetic Protein 2 (BMP2), Bone sialoprofein (BSP), osteocalcin (OCN), and osterix (OSX). However, the abovementioned effects of BMSCs-Exo could be abolished by miR-590-3p silencing. Mechanistic analysis unmasked the negative regulation of miR-590-3p on its downstream target TGFBR1. Finally, the effects of miR-590-3p/TGFBR1 axis on the differentiation and osteogenesis of osteoblasts were validated by rescue assays. In conclusion, the present study demonstrates that exosomal miR-590-3p secreted by BMSCs can induce osteoblast differentiation and osteogenesis.

Depletion of MicroRNA-100-5p Promotes Osteogenesis Via Lysine(K)-Specific Demethylase 6B

Senescence and osteogenic differentiation potential loss limited bone nonunion treatment effects of bone marrow-derived mesenchymal stem cells (BMSCs). MiR-100-5p/Lysine(K)-specific demethylase 6B (KDM6B) can inhibit osteogenesis, but their effects on bone union remain unclear. This study aims to investigate the effects of miR-100-5p/KDM6B on osteogenic differentiation and bone defects. Wild-type or microRNA 100 (miR-100) knockdown mice underwent critical-size defect (CSD) cranial surgery and collagen I/poly-γ-glutamic acid scaffold treatment. The crania was observed using microcomputed tomography, hematoxylin and eosin staining, Masson staining, alkaline phosphatase (ALP) staining, immunohistochemistry, and immunofluorescence. Primary-cultured BMSCs transfected with miR-100-5p mimic/inhibitor and KDM6B cDNA were evaluated for osteogenic differentiation using Alizarin Red staining, ALP activity detection, and Western blot analysis. Genetic transcription levels were detected using quantitative reverse transcription polymerase chain reaction. This study found that miR-100 depletion promotes defect healing in mouse calvaria, increases the proportion of new bone and osteoblasts in calvaria, and activates the expression of KDM6B and osteocalcin (OCN) proteins, promoting the transcription of bone morphogenetic protein-2, Runt-related transcription factor 2 (Runx2), OCN, and KDM6B, while methylation of lysine 27 on histone H3 (H3K27me3) decreased. Furthermore, miR-100-5p mimics suppressed osteogenic differentiation by inhibiting KDM6B with increased H3K27me3, ALP, Runx2, OCN, and osteopontin protein expression, while miR-100-5p inhibitors have opposite effects. Moreover, KDM6B can reverse miR-100-5p mimic effects. Notably, scaffolds carrying miR-100-5p mimics/inhibitors transfected BMSCs were placed in CSD mice and found that miR-100-5p inhibitors have a better effect on CSD healing and increase new bone without inflammatory cell infiltration. This study proved that miR-100-5p depletion promotes bone union and osteogenic differentiation of BMSCs via KDM6B/H3K27me3.

Characterization of the Secretome from Spheroids of Adipose-Derived Stem Cells (SASCs) and Its Potential for Tissue Regeneration

INTRODUCTION

Spheroids are spherical aggregates of cells that mimic the three-dimensional (3D) architecture of tissues more closely than traditional two dimensional (2D) cultures. Spheroids of adipose stem cells (SASCs) show special features such as high multilineage differentiation potential and immunomodulatory activity. These properties have been attributed to their secreted factors, such as cytokines and growth factors. Moreover, a key role is played by the extracellular vesicles (EVs), which lead a heterogeneous cargo of proteins, mRNAs, and small RNAs that interfere with the pathways of the recipient cells.

PURPOSE

The aim of this work was to characterize the composition of the secretome and exosome from SASCs and evaluate their regenerative potential.

MATERIALS AND METHODS

SASCs were extracted from adipose samples of healthy individuals after signing informed consent. The exosomes were isolated and characterized by Dinamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Western blotting analyses. The expression of mRNAs and miRNAs were evaluated through real-time PCR. Lastly, a wound-healing assay was performed to investigate their regenerative potential on different cell cultures.

RESULTS

The SASCs' exosomes showed an up-regulation of NANOG and SOX2 mRNAs, typical of stemness maintenance, as well as miR126 and miR146a, related to angiogenic and osteogenic processes. Moreover, the exosomes showed a regenerative effect.

CONCLUSIONS

The SASCs' secretome carried paracrine signals involved in stemness maintenance, pro-angiogenic and pro-osteogenic differentiation, immune system regulation, and regeneration.

Cause and consequence of heterogeneity in human mesenchymal stem cells: Challenges in clinical application

Human mesenchymal stem cells (hMSCs) are mesoderm-derived adult stem cells with self-proliferation capacity, pluripotent differentiation potency, and excellent histocompatibility. These advantages make hMSCs a promising tool in clinical application. However, the majority of clinical trials using hMSC therapy for diverse human diseases do not achieve expectations, despite the prospective pre-clinical outcomes in animal models. This is partly attributable to the intrinsic heterogeneity of hMSCs. In this review, the cause of heterogeneity in hMSCs is systematically discussed at multiple levels, including isolation methods, cultural conditions, donor-to-donor variation, tissue sources, intra-tissue subpopulations, etc. Additionally, the effect of hMSCs heterogeneity on the contrary role in tumor progression and immunomodulation is also discussed. The attempts to understand the cellular heterogeneity of hMSCs and its consequences are important in supporting and improving therapeutic strategies for hMSCs.

The Therapeutic Mechanisms of Mesenchymal Stem Cells in MS-A Review Focusing on Neuroprotective Properties

In multiple sclerosis (MS), there is a great need for treatment with the ability to suppress compartmentalized inflammation within the central nervous system (CNS) and to promote remyelination and regeneration. Mesenchymal stem cells (MSCs) represent a promising therapeutic option, as they have been shown to migrate to the site of CNS injury and exert neuroprotective properties, including immunomodulation, neurotrophic factor secretion, and endogenous neural stem cell stimulation. This review summarizes the current understanding of the underlying neuroprotective mechanisms and discusses the translation of MSC transplantation and their derivatives from pre-clinical demyelinating models to clinical trials with MS patients.

Dual impacts of mesenchymal stem cell-derived exosomes on cancer cells: unravelling complex interactions

Mesenchymal stem cells (MSCs) are multipotent, self-renewing stromal cells found in a variety of adult tissues. MSCs possess a remarkable ability to migrate towards tumor sites, known as homing. This homing process is mediated by various factors, including chemokines, growth factors, and extracellular matrix components present in the tumor microenvironment. MSCs release extracellular vesicles known as exosomes (MSC-Exos), which have been suggested to serve a key role in mediating a wide variety of MSC activities. Through cell-cell communication, MSC-Exos have been shown to alter recipient cell phenotype or function and play as a novel cell-free alternative for MSC-based cell therapy. However, MSC recruitment to tumors allows for their interaction with cancer cells and subsequent regulation of tumor behavior. MSC-Exos act as tumor niche modulators via transferring exosomal contents, such as specific proteins or genetic materials, to the nearby cancer cells, leading to either promotion or suppression of tumorigenesis, angiogenesis, and metastasis, depending on the specific microenvironmental cues and recipient cell characteristics. Consequently, there is still a debate about the precise relationship between tumor cells and MSC-Exos, and it is unclear how MSC-Exos impacts tumor cells. Although the dysregulation of miRNAs is caused by the progression of cancer, they also play a direct role in either promoting or inhibiting tumor growth as they act as either oncogenes or tumor suppressors. The utilization of MSC-Exos may prove to be an effective method for restoring miRNA as a means of treating cancer. This review aimed to present the existing understanding of the impact that MSC-Exos could have on cancer. To begin with, we presented a brief explanation of exosomes, MSCs, and MSC-Exos. Following this, we delved into the impact of MSC-Exos on cancer growth, EMT, metastasis, angiogenesis, resistance to chemotherapy and radiotherapy, and modulation of the immune system. Opposing effects of mesenchymal stem cells-derived exosomes on cancer cells.

Cell-Based Therapies for Glaucoma

Glaucomatous optic neuropathy (GON) is the major cause of irreversible visual loss worldwide and can result from a range of disease etiologies. The defining features of GON are retinal ganglion cell (RGC) degeneration and characteristic cupping of the optic nerve head (ONH) due to tissue remodeling, while intraocular pressure remains the only modifiable GON risk factor currently targeted by approved clinical treatment strategies. Efforts to understand the mechanisms that allow species such as the zebrafish to regenerate their retinal cells have greatly increased our understanding of regenerative signaling pathways. However, proper integration within the retina and projection to the brain by the newly regenerated neuronal cells remain major hurdles. Meanwhile, a range of methods for in vitro differentiation have been developed to derive retinal cells from a variety of cell sources, including embryonic and induced pluripotent stem cells. More recently, there has been growing interest in the implantation of glial cells as well as cell-derived products, including neurotrophins, microRNA, and extracellular vesicles, to provide functional support to vulnerable structures such as RGC axons and the ONH. These approaches offer the advantage of not relying upon the replacement of degenerated cells and potentially targeting earlier stages of disease pathogenesis. In order to translate these techniques into clinical practice, appropriate cell sourcing, robust differentiation protocols, and accurate implantation methods are crucial to the success of cell-based therapy in glaucoma. Translational Relevance: Cell-based therapies for glaucoma currently under active development include the induction of endogenous regeneration, implantation of exogenously derived retinal cells, and utilization of cell-derived products to provide functional support.

Clinical Trials Targeting Secondary Damage after Traumatic Spinal Cord Injury

Spinal cord injury (SCI) often causes loss of sensory and motor function resulting in a significant reduction in quality of life for patients. Currently, no therapies are available that can repair spinal cord tissue. After the primary SCI, an acute inflammatory response induces further tissue damage in a process known as secondary injury. Targeting secondary injury to prevent additional tissue damage during the acute and subacute phases of SCI represents a promising strategy to improve patient outcomes. Here, we review clinical trials of neuroprotective therapeutics expected to mitigate secondary injury, focusing primarily on those in the last decade. The strategies discussed are broadly categorized as acute-phase procedural/surgical interventions, systemically delivered pharmacological agents, and cell-based therapies. In addition, we summarize the potential for combinatorial therapies and considerations.

BMSCs Promote Differentiation of Enteric Neural Precursor Cells to Maintain Neuronal Homeostasis in Mice With Enteric Nerve Injury

BACKGROUND & AIMS

Our previous study showed that transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) promoted functional enteric nerve regeneration in denervated mice but not through direct transdifferentiation. Homeostasis of the adult enteric nervous system (ENS) is maintained by enteric neural precursor cells (ENPCs). Whether ENPCs are a source of regenerated nerves in denervated mice remains unknown.

METHODS

Genetically engineered mice were used as recipients, and ENPCs were traced during enteric nerve regeneration. The mice were treated with benzalkonium chloride to establish a denervation model and then transplanted with BMSCs 3 days later. After 28 days, the gastric motility and ENS regeneration were analyzed. The interaction between BMSCs and ENPCs in vitro was further assessed.

RESULTS

Twenty-eight days after transplantation, gastric motility recovery (gastric emptying capacity, P < .01; gastric contractility, P < .01) and ENS regeneration (neurons, P < .01; glial cells, P < .001) were promoted in BMSCs transplantation groups compared with non-transplanted groups in denervated mice. More importantly, we found that ENPCs could differentiate into enteric neurons and glial cells in denervated mice after BMSCs transplantation, and the proportion of Nestin⁺/Ngfr⁺ cells differentiated into neurons was significantly higher than that of Nestin⁺ cells. A small number of BMSCs located in the myenteric plexus differentiated into glial cells. In vitro, glial cell-derived neurotrophic factor (GDNF) from BMSCs promotes the migration, proliferation, and differentiation of ENPCs.

CONCLUSIONS

In the case of enteric nerve injury, ENPCs can differentiate into enteric neurons and glial cells to promote ENS repair and gastric motility recovery after BMSCs transplantation. BMSCs expressing GDNF enhance the migration, proliferation, and differentiation of ENPCs.

Mesenchymal Stem Cell Application and Its Therapeutic Mechanisms in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH), a common lethal subtype of stroke accounting for nearly 10–15% of the total stroke disease and affecting two million people worldwide, has a high mortality and disability rate and, thus, a major socioeconomic burden. However, there is no effective treatment available currently. The role of mesenchymal stem cells (MSCs) in regenerative medicine is well known owing to the simplicity of acquisition from various sources, low immunogenicity, adaptation to the autogenic and allogeneic systems, immunomodulation, self-recovery by secreting extracellular vesicles (EVs), regenerative repair, and antioxidative stress. MSC therapy provides an increasingly attractive therapeutic approach for ICH. Recently, the functions of MSCs such as neuroprotection, anti-inflammation, and improvement in synaptic plasticity have been widely researched in human and rodent models of ICH. MSC transplantation has been proven to improve ICH-induced injury, including the damage of nerve cells and oligodendrocytes, the activation of microglia and astrocytes, and the destruction of blood vessels. The improvement and recovery of neurological functions in rodent ICH models were demonstrated via the mechanisms such as neurogenesis, angiogenesis, anti-inflammation, anti-apoptosis, and synaptic plasticity. Here, we discuss the pathological mechanisms following ICH and the therapeutic mechanisms of MSC-based therapy to unravel new cues for future therapeutic strategies. Furthermore, some potential strategies for enhancing the therapeutic function of MSC transplantation have also been suggested.

A Brief Overview of Global Trends in MSC-Based Cell Therapy

Human mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are important adult stem cells for regenerative medicine, largely due to their regenerative characteristics such as self-renewal, secretion of trophic factors, and the capability of inducing mesenchymal cell lineages. MSCs also possess homing and trophic properties modulating immune system, influencing microenvironment around damaged tissues and enhancing tissue repair, thus offering a broad perspective in cell-based therapies. Therefore, it is not surprising that MSCs have been the broadly used adult stem cells in clinical trials. To gain better insights into the current applications of MSCs in clinical applications, we perform a comprehensive review of reported data of MSCs clinical trials conducted globally. We summarize the biological effects and mechanisms of action of MSCs, elucidating recent clinical trials phases and findings, highlighting therapeutic effects of MSCs in several representative diseases, including neurological, musculoskeletal diseases and most recent Coronavirus infectious disease. Finally, we also highlight the challenges faced by many clinical trials and propose potential solutions to streamline the use of MSCs in routine clinical applications and regenerative medicine.

Human umbilical cord mesenchymal stem cells express cholinergic neuron markers during co-culture with amniotic membrane cells and retinoic acid induction

Background: A wide variety of cytokines are released from human amniotic membrane cells (hAMCs), which can increase the rate of differentiation of mesenchymal stem cells into the neurons. We studied the effect of Retinoic Acid (RA) on the differentiation rate of human Umbilical Cord Mesenchymal Stem Cells (hUMSCs) which were co-cultured with hAMCs. Methods: In this experimental study, both hUMSCs and hAMCs were isolated from postpartum human umbilical cords and placenta respectively. The expression of mesenchymal (CD73, CD90 and CD105), hematopoietic and endothelial (CD34 and CD45) markers in hUMSCs were confirmed by flow cytometry. The hUMSCs were cultured in four distinct groups: group 1) Control, group 2) Co-culture with hAMCs, group 3) RA treatment and group 4) Co-culture with hAMCs treated by RA. Twelve days after culturing, the expression of NSE, MAP2 and ChAT differentiation genes and their related proteins were examined by real-time PCR and immunocytochemistry respectively. Results: The flow-cytometry analysis indicated increased expression of mesenchymal markers and a low expression of both hematopoietic and endothelial markers (CD73:98.24%, CD90: 97.32%, CD105: 90.75%, CD34: 2.96%, and CD45:1.74%). Moreover, the expression of both NSE and MAP2 markers was increased significantly in all studied groups in comparison to the control group On the other hand, the expression of ChAT had a significant increase in the group 2 and 4 (RA and RA+ co-culture). Conclusion: RA can be used as an effective inducer to differentiate hUMSCs into cholinergic-like cells, and hAMCs could increase the number of differentiated cells as an effective factor.

The Identification of Marker Genes for Predicting the Osteogenic Differentiation Potential of Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) have the potential to differentiate into a variety of mature cell types and are a promising source of regenerative medicine. The success of regenerative medicine using MSCs strongly depends on their differentiation potential. In this study, we sought to identify marker genes for predicting the osteogenic differentiation potential by comparing ilium MSC and fibroblast samples. We measured the mRNA levels of 95 candidate genes in nine ilium MSC and four fibroblast samples before osteogenic induction, and compared them with alkaline phosphatase (ALP) activity as a marker of osteogenic differentiation after induction. We identified 17 genes whose mRNA expression levels positively correlated with ALP activity. The chondrogenic and adipogenic differentiation potentials of jaw MSCs are much lower than those of ilium MSCs, although the osteogenic differentiation potential of jaw MSCs is comparable with that of ilium MSCs. To select markers suitable for predicting the osteogenic differentiation potential, we compared the mRNA levels of the 17 genes in ilium MSCs with those in jaw MSCs. The levels of 7 out of the 17 genes were not substantially different between the jaw and ilium MSCs, while the remaining 10 genes were expressed at significantly lower levels in jaw MSCs than in ilium MSCs. The mRNA levels of the seven similarly expressed genes were also compared with those in fibroblasts, which have little or no osteogenic differentiation potential. Among the seven genes, the mRNA levels of IGF1 and SRGN in all MSCs examined were higher than those in any of the fibroblasts. These results suggest that measuring the mRNA levels of IGF1 and SRGN before osteogenic induction will provide useful information for selecting competent MSCs for regenerative medicine, although the effectiveness of the markers is needed to be confirmed using a large number of MSCs, which have various levels of osteogenic differentiation potential.

Impact of the Epigenetically Regulated Hoxa-5 Gene in Neural Differentiation from Human Adipose-Derived Stem Cells

Human adipose-derived mesenchymal stem cells (hASCs) may be used in some nervous system pathologies, although obtaining an adequate degree of neuronal differentiation is an important barrier to their applicability. This requires a deep understanding of the expression and epigenetic changes of the most important genes involved in their differentiation. We used hASCs from human lipoaspirates to induce neuronal-like cells through three protocols (Neu1, 2, and 3), determined the degree of neuronal differentiation using specific biomarkers in culture cells and neurospheres, and analyzed epigenetic changes of genes involved in this differentiation. Furthermore, we selected the Hoxa-5 gene to determine its potential to improve neuronal differentiation. Our results showed that an excellent hASC neuronal differentiation process using Neu1 which efficiently modulated NES, CHAT, SNAP25, or SCN9A neuronal marker expression. In addition, epigenetic studies showed relevant changes in Hoxa-5, GRM4, FGFR1, RTEL1, METRN, and PAX9 genes. Functional studies of the Hoxa-5 gene using CRISPR/dCas9 and lentiviral systems showed that its overexpression induced hASCs neuronal differentiation that was accelerated with the exposure to Neu1. These results suggest that Hoxa-5 is an essential gene in hASCs neuronal differentiation and therefore, a potential candidate for the development of cell therapy strategies in neurological disorders.

22(R)-hydroxycholesterol for dopaminergic neuronal specification of MSCs and amelioration of Parkinsonian symptoms in rats

Oxysterols play vital roles in the human body, ranging from cell cycle regulation and progression to dopaminergic neurogenesis. While naïve human mesenchymal stem cells (hMSCs) have been explored to have neurogenic effect, there is still a grey area to explore their regenerative potential after in vitro differentiation. Hence, in the current study, we have investigated the neurogenic effect of 22(R)-hydroxycholesterol (22-HC) on hMSCs obtained from bone marrow, adipose tissue and dental pulp. Morphological and morphometric analysis revealed physical differentiation of stem cells into neuronal cells. Detailed characterization of differentiated cells affirmed generation of neuronal cells in culture. The percentage of generation of non-DA cells in the culture confirmed selective neurogenic potential of 22-HC. We substantiated the efficacy of these cells in neuro-regeneration by transplanting them into Parkinson's disease Wistar rat model. MSCs from dental pulp had maximal regenerative effect (with 80.20 ± 1.5% in vitro differentiation efficiency) upon transplantation, as shown by various behavioural examinations and immunohistochemical tests. Subsequential analysis revealed that 22-HC yields a higher percentage of functional DA neurons and has differential effect on various tissue-specific primary human MSCs. 22-HC may be used for treating Parkinson's disease in future with stem cells.

Adipose-Derived Mesenchymal Stromal Cells in Regenerative Medicine: State of Play, Current Clinical Trials, and Future Prospects

Significance: Wound healing is a complex process involving pain and inflammation, where innervation plays a central role. Managing wound healing and pain remains an important issue, especially in pathologies such as excessive scarring (often leading to fibrosis) or deficient healing, leading to chronic wounds. Recent Advances: Advances in therapies using mesenchymal stromal cells offer new insights for treating indications that previously lacked options. Adipose-derived mesenchymal stromal cells (AD-MSCs) are now being used to a much greater extent in clinical trials for regenerative medicine. However, to be really valid, these randomized trials must imperatively follow strict guidelines such as consolidated standards of reporting trials (CONSORT) statement. Indeed, AD-MSCs, because of their paracrine activities and multipotency, have potential to cure degenerative and/or inflammatory diseases. Combined with their relatively easy access (from adipose tissue) and proliferation capacity, AD-MSCs represent an excellent candidate for allogeneic treatments. Critical Issues: The success of AD-MSC therapy may depend on the robustness of the biological functions of AD-MSCs, which requires controlling source heterogeneity and production processes, and development of biomarkers that predict desired responses. Several studies have investigated the effect of AD-MSCs on innervation, wound repair, or pain management separately, but systematic evaluation of how those effects could be combined is lacking. Future Directions: Future studies that explore how AD-MSC therapy can be used to treat difficult-to-heal wounds, underlining the need to thoroughly characterize the cells used, and standardization of preparation processes are needed. Finally, how this a priori easy-to-use cell therapy treatment fits into clinical management of pain, improvement of tissue healing, and patient quality of life, all need to be explored.

Mesenchymal Stem Cells: Signaling Pathways in Transdifferentiation Into Retinal Progenitor Cells

Several signaling pathways and transcription factors control the cell fate in its in vitro development and differentiation. The orchestrated use of these factors results in cell specification. In coculture methods, many of these factors secrete from host cells but control the process. Today, transcription factors required for retinal progenitor cells are well known, but the generation of these cells from mesenchymal stem cells is an ideal goal. The purpose of the paper is to review novel methods for retinal progenitor cell production and selecting a set of signaling molecules in the presence of adult retinal pigment epithelium and extraocular mesenchyme acting as inducers of retinal cell differentiation.

Exosomes: A Friend or Foe for Osteoporotic Fracture?

The clinical need for effective osteoporotic fracture therapy and prevention remains urgent. The occurrence and healing of osteoporotic fracture are closely associated with the continuous processes of bone modeling, remodeling, and regeneration. Accumulating evidence has indicated a prominent role of exosomes in mediating multiple pathophysiological processes, which are essential for information and materials exchange and exerting pleiotropic effects on neighboring or distant bone-related cells. Therefore, the exosomes are considered as important candidates both in the occurrence and healing of osteoporotic fracture by accelerating or suppressing related processes. In this review, we collectively focused on recent findings on the diagnostic and therapeutic applications of exosomes in osteoporotic fracture by regulating osteoblastogenesis, osteoclastogenesis, and angiogenesis, providing us with novel therapeutic strategies for osteoporotic fracture in clinical practice.

Effect of Bone Marrow Stromal Cells in Parkinson's Disease Rodent Model: A Meta-Analysis

Background: Bone marrow stromal cells (BMSCs) has been reported to have beneficial effects in improving behavioral deficits, and rescuing dopaminergic neuron loss in rodent models of Parkinson's disease (PD). However, their pooled effects for dopaminergic neuron have yet to be described.

Objective: To review the neuroprotective effect of naïve BMSCs in rodent models of PD.

Methods: The PubMed, EMBASE, and Web of Science databases were searched up to September 30, 2020. Inclusion criteria according to PICOS criteria were as follows: (1) population: rodents; (2) intervention: unmodified BMSCs; (3) comparison: not specified; (4) primary outcome: tyrosine hydroxylase level in the substantia nigra pars compacta and rotational behavior; secondary outcome: rotarod test, and limb function; (5) study: experimental studies. Multiple prespecified subgroup and meta-regression analysis were conducted. Following quality assessment, random effects models were used for this meta-analysis.

Results: Twenty-seven animal studies were included. The median quality score was 4.7 (interquartile range, 2–8). Overall standardized mean difference between animals treated with naïve BMSCs and controls was 2.79 (95% confidence interval: 1.70, 3.87; P < 0.001) for densitometry of tyrosine hydroxylase-positive staining; −1.54 (95% confidence interval: −2.11, −0.98; P < 0.001) for rotational behavior. Significant heterogeneity among studies was observed.

Conclusions: Results of this meta-analysis suggest that naïve BMSCs therapy increased dopaminergic neurons and ameliorated behavioral deficits in rodent models of PD.

The role of insulin-like growth factors in modulating the activity of dental mesenchymal stem cells

Regenerative treatment protocols are an exciting prospect in the management of oral pathology, as they allow for tissues to be restored to their original form and function, as compared to the reparative healing mechanisms which currently govern the outcomes of the majority of dental treatment. Stem cell therapy presents with a great deal of untapped potential in this pursuit of tissue regeneration, and, in particular, mesenchymal stem cells (MSCs) derived from dental tissues are of specific relevance with regards to their applications in engineering craniofacial tissues. A number of mediatory factors are involved in modulating the actions of dental MSCs, and, of these, insulin like growth factors (IGFs) are known to have potent effects in governing the behavior of these cells. The IGF family comprises a number of primary ligands, receptors, and binding proteins which are known to modulate the key properties of dental MSCs, such as their proliferation rates, differentiation potential, and mineralisation. The aims of this review are three-fold: (i) to present an overview of dental MSCs and the role of growth factors in modulating their characteristics, (ii) to discuss in greater detail the specific role of IGFs and the benefits they may convey for tissue engineering, and (iii) to provide a summary of potential for in vivo clinical translation of the current in vitro body of evidence.

Progress in Stem Cell Therapy for Spinal Cord Injury

Background

Spinal cord injury (SCI) is one of the serious neurological diseases that occur in young people with high morbidity and disability. However, there is still a lack of effective treatments for it. Stem cell (SC) treatment of SCI has gradually become a new research hotspot over the past decades. This article is aimed at reviewing the research progress of SC therapy for SCI.

Methods

Review the literature and summarize the effects, strategies, related mechanisms, safety, and clinical application of different SC types and new approaches in combination with SC in SCI treatment.

Results

A large number of studies have focused on SC therapy for SCI, most of which showed good effects. The common SC types for SCI treatment include mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs). The modes of treatment include in vivo and in vitro induction. The pathways of transplantation consist of intravenous, transarterial, nasal, intraperitoneal, intrathecal, and intramedullary injections. Most of the SC treatments for SCI use a number of cells ranging from tens of thousands to millions. Early or late SC administration, application of immunosuppressant or not are still controversies. Potential mechanisms of SC therapy include tissue repair and replacement, neurotrophy, and regeneration and promotion of angiogenesis, antiapoptosis, and anti-inflammatory. Common safety issues include thrombosis and embolism, tumorigenicity and instability, infection, high fever, and even death. Recently, some new approaches, such as the pharmacological activation of endogenous SCs, biomaterials, 3D print, and optogenetics, have been also developed, which greatly improved the application of SC therapy for SCI.

Conclusion

Most studies support the effects of SC therapy on SCI, while a few studies do not. The cell types, mechanisms, and strategies of SC therapy for SCI are very different among studies. In addition, the safety cannot be ignored, and more clinical trials are required. The application of new technology will promote SC therapy of SCI.

Significant transcriptomic changes are associated with differentiation of bone marrow-derived mesenchymal stem cells into neural progenitor-like cells in the presence of bFGF and EGF

INTRODUCTION

Mesenchymal stem cells (MSCs) isolated from bone marrow have different developmental origins, including neural crest. MSCs can differentiate into neural progenitor-like cells (NPCs) under the influence of bFGF and EGF. NPCs can terminally differentiate into neurons that express beta-III-tubulin and elicit action potential. The main aim of the study was to identify key genetic markers involved in differentiation of MSCs into NPCs through transcriptomic analysis.

METHOD

Total RNA was isolated from MSCs and MSCs-derived NPCs followed by cDNA library construction for transcriptomic analysis. Sample libraries that passed the quality and quantity assessments were subjected to high throughput mRNA sequencing using NextSeq®500. Differential gene expression analysis was performed using the DESeq2 R package with MSC samples being a reference group. The expression of eight differentially regulated genes was counter validated using real-time PCR.

RESULTS

In total, of the 3,252 differentially regulated genes between MSCs and NPCs with two or more folds, 1,771 were upregulated genes, whereas 1,481 were downregulated in NPCs. Amongst these differential genes, 104 transcription factors were upregulated, and 45 were downregulated in NPCs. Neurogenesis related genes were upregulated in NPCs and the main non-redundant gene ontology (GO) terms enriched in NPCs were the autonomic nervous system, cell surface receptor signalling pathways), extracellular structure organisation, and programmed cell death. The main non-redundant GO terms enriched in MSCs included cytoskeleton organisation cytoskeleton structural constituent, mitotic cell cycle), and the mitotic cell cycle process Gene set enrichment analysis also confirmed cell cycle regulated pathways as well as Biocarta integrin pathway were upregulated in MSCs. Transcription factors enrichment analysis by ChEA3 revealed Foxs1 and HEYL, amongst the top five transcription factors, inhibits and enhances, respectively, the NPCs differentiation of MSCs.

CONCLUSIONS

The vast differences in the transcriptomic profiles between NPCs and MSCs revealed a set of markers that can identify the differentiation stage of NPCs as well as provide new targets to enhance MSCs differentiation into NPCs.

Topography: A Biophysical Approach to Direct the Fate of Mesenchymal Stem Cells in Tissue Engineering Applications

Tissue engineering is a promising strategy to treat tissue and organ loss or damage caused by injury or disease. During the past two decades, mesenchymal stem cells (MSCs) have attracted a tremendous amount of interest in tissue engineering due to their multipotency and self-renewal ability. MSCs are also the most multipotent stem cells in the human adult body. However, the application of MSCs in tissue engineering is relatively limited because it is difficult to guide their differentiation toward a specific cell lineage by using traditional biochemical factors. Besides biochemical factors, the differentiation of MSCs also influenced by biophysical cues. To this end, much effort has been devoted to directing the cell lineage decisions of MSCs through adjusting the biophysical properties of biomaterials. The surface topography of the biomaterial-based scaffold can modulate the proliferation and differentiation of MSCs. Presently, the development of micro- and nano-fabrication techniques has made it possible to control the surface topography of the scaffold precisely. In this review, we highlight and discuss how the main topographical features (i.e., roughness, patterns, and porosity) are an efficient approach to control the fate of MSCs and the application of topography in tissue engineering.

Mesenchymal Stem Cells as a Promising Cell Source for Integration in Novel In Vitro Models

The human-relevance of an in vitro model is dependent on two main factors-(i) an appropriate human cell source and (ii) a modeling platform that recapitulates human in vivo conditions. Recent years have brought substantial advancements in both these aspects. In particular, mesenchymal stem cells (MSCs) have emerged as a promising cell source, as these cells can differentiate into multiple cell types, yet do not raise the ethical and practical concerns associated with other types of stem cells. In turn, advanced bioengineered in vitro models such as microfluidics, Organs-on-a-Chip, scaffolds, bioprinting and organoids are bringing researchers ever closer to mimicking complex in vivo environments, thereby overcoming some of the limitations of traditional 2D cell cultures. This review covers each of these advancements separately and discusses how the integration of MSCs into novel in vitro platforms may contribute enormously to clinical and fundamental research.

Application of Bone Marrow-Derived Mesenchymal Stem Cells for Muscle Healing After Contusion Injury in Mice

BACKGROUND

Skeletal muscle injuries are very common in sports medicine. Conventional therapies have limited clinical efficacy. New treatment methods should be developed to allow athletes to return to play with better function.

PURPOSE

To evaluate the in vitro differentiation potential of bone marrow-derived mesenchymal stem cells and the in vivo histologic and physiologic effects of mesenchymal stem cell therapy on muscle healing after contusion injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bone marrow cells were flushed from both femurs of 5-week-old C57BL/6 mice to establish immortalized mesenchymal stem cell lines. A total of 36 mice aged 8 to 10 weeks were used to develop a muscle contusion model and were divided into 6 groups (6 mice/group) on the basis of the different dosages of IM2 cells to be injected (0, 1.25 × 105, and 2.5 × 105 cells with/without F-127 in 100 μL of phosphate-buffered saline). Histological analysis of muscle regeneration was performed, and the fast-twitch and tetanus strength of the muscle contractions was measured 28 days after muscle contusion injury, after injections of different doses of mesenchymal stem cells with or without the F-127 scaffold beginning 14 days after contusion injury.

RESULTS

The mesenchymal stem cell-treated muscles exhibited numerous regenerating myofibers. All the groups treated with mesenchymal stem cells (1.25 × 105 cells, 2.5 × 105 cells, 1.25 × 105 cells plus F-127, and 2.5 × 105 cells plus F-127) exhibited a significantly higher number of regenerating myofibers (mean ± SD: 111.6 ± 14.77, 133.4 ± 21.44, 221.89 ± 32.65, and 241.5 ± 25.95, respectively) as compared with the control group and the control with F-127 (69 ± 18.79 and 63.2 ± 18.98). The physiologic evaluation of fast-twitch and tetanus strength did not reveal differences between the age-matched uninjured group and the groups treated with various doses of mesenchymal stem cells 28 days after contusion. Significant differences were found between the control group and the groups treated with various doses of mesenchymal stem cells after muscle contusion.

CONCLUSION

Mesenchymal stem cell therapy increased the number of regenerating myofibers and improved fast-twitch and tetanus muscle strength in a mouse model of muscle contusion. However, the rapid decay of transplanted mesenchymal stem cells suggests a paracrine effect of this action. Treatment with mesenchymal stem cells at various doses combined with the F-127 scaffold is a potential therapy for a muscle contusion.

CLINICAL RELEVANCE

Mesenchymal stem cell therapy has an effect on sports medicine because of its effects on myofiber regeneration and muscle strength after contusion injury.

Differentiation of Human Mesenchymal Stem Cells from Wharton's Jelly Towards Neural Stem Cells Using A Feasible and Repeatable Protocol

The transplantation of neural stem cells (NSCs) capable of regenerating to the cells of the central nervous system (CNS) is a promising strategy in the treatment of CNS diseases and injury. As previous studies have highlighted mesenchymal stem cells (MSCs) as a source of NSCs, this study aimed to develop a feasible, efficient, and reproducible method for the neural induction of MSCs isolated from Wharton's jelly (hWJ-MSCs). We induced neural differentiation in a monolayer culture using epidermal growth factor, basic fibroblast growth factor, N2, and B27 supplements. This resulted in a homogenous population of proliferating cells that expressed certain neural markers at both the protein and mRNA levels. Flow cytometry and immunocytochemistry confirmed the expression of neural markers: nestin, sex-determining region Y (SRY) box 1 and 2 (SOX1 and SOX2), microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein (GFAP). The qRT-PCR analysis revealed significantly enhanced expression of nestin and MAP2 in differentiated cells. This study confirms that it is possible to generate NSCs-like cells from hWJ-MSCs in a 2D culture using a practical method. However, the therapeutic effectiveness of such differentiated cells should be extended to confirm the terminal differentiation ability and electrophysiological properties of neurons derived from them.

Phase I and registry study of autologous bone marrow concentrate evaluated in PDE5 inhibitor refractory erectile dysfunction

Background

Bone marrow mononuclear cells have been successfully utilized for numerous regenerative purposes. In the current study, patients suffering from erectile dysfunction (ED) unresponsive to phosphodiesterase 5 inhibitors were administered autologous bone marrow concentrate delivered intracavernously utilizing a point of care FDA cleared medical device.

Methods

A total of 40 patients were treated in the primary trial and 100 in the clinical registry, with the longest follow up of 12 months.

Results

Minimal treatment associated adverse effects where observed related to short term bruising at the site of harvest or injection. No long-term adverse events were noted related to the intervention. Mean improvements in IIEF-5 score were 2 in the Caverstem 1.0 low dose group, 3 in the high dose Caverstem 1.0 group and 9 in the Caverstem 2.0 group. Furthermore, improvements peaked by 3 months and maintained at 6 months follow-up.

Conclusion

These data support the safety and efficacy of point of care, minimally to non-manipulated, non-expanded bone marrow concentrate for the treatment of ED.

Trial registration Funded by Creative Medical Health, Inc.; Clinicaltrials.gov number: NCT03699943; https://clinicaltrials.gov/ct2/show/NCT03699943?term=caverstem&rank=1; initially registered December 12, 2015.

Outcomes of Bone Marrow-Derived Mononuclear Cell Transplantation for Patients in Persistent Vegetative State After Drowning: Report of Five Cases

Aim: Anoxic brain injury (ABI) due to non-fatal drowning may cause persistent vegetative state (VS) that is currently incurable. The aim of this paper is to present the safety and feasibility of autologous bone marrow-derived mononuclear cell (BMMNC) transplantation in five drowning children surviving in persistent VS. Methods: We used BMMNC as a novel candidate therapeutic tool in a pilot phase-I study for five patients affected by neurological sequelae after near-death drowning. Autologous BMMNCs were freshly isolated using Ficoll gradient centrifugation then infused intrathecally to five patients. The number of transplantation varied from two to four times depending on the motor function improvement of patient after transplantation. Clinical therapeutic effects were evaluated using gross motor function measure and muscle spasticity rating scales, cognitive assessments, and brain MRI before and after cell administrations. Results: Six months after BMMNC transplantation, no serious complications or adverse events were reported. All five patients displayed improvement across the major parameters of gross motor function, cognition, and muscle spasticity. Three patients displayed improved communication including the expression of words. In particular, one patient remarkably reduced cerebral atrophy, with nearly normal cerebral parenchyma after BMMNC transplantation. Conclusions: Autologous BMMNC transplantation for the treatment of children in persistent VS after drowning is safe, feasible, and can potentially improve motor function and cognition and reduce muscle spasticity. These results pave the way for a future phase II clinical trial to evaluate the efficacy of the therapy.

LncRNA MALAT1 shuttled by bone marrow-derived mesenchymal stem cells-secreted exosomes alleviates osteoporosis through mediating microRNA-34c/SATB2 axis

Long non-coding RNAs (lncRNAs) have emerged as promising novel modulators during osteogenesis in mesenchymal stem cells (MSCs). Enhanced SATB2 has been demonstrated to promote osteogenic differentiation of bone marrow-derived mesenchymal stem cells (hBMSCs) in patients with osteonecrosis. Preliminary bioinformatic analysis identified putative binding sites between microRNA-34c (miR-34c) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) or miR-34c and SATB2 3'UTR. Thus, the current study aimed to clarify the potential functional relevance of MALAT1-containing exosomes from BMSCs in osteoporosis. The extracted exosomes from primary BMSCs were co-cultured with human osteoblasts (hFOB1.19), followed by evaluation of the hFOB1.19 cell proliferation, alkaline phosphatase (ALP) activity and mineralized nodules. The obtained findings indicated that BMSC-Exos promoted the expression of SATB2 in osteoblasts, and SATB2 silencing reduced the ALP activity of osteoblasts and mineralized nodules. MALAT1 acted as a sponge of miR-34c to promote the expression of SATB2. Additionally, BMSCs-derived exosomal MALAT1 promoted osteoblast activity. Moreover, in vivo experiments indicated that miR-34c reversed the effect of MALAT1, and SATB2 reversed the effect of miR-34c in ovariectomized mice. Taken together, this study demonstrates that BMSCs-derived exosomal MALAT1 enhances osteoblast activity in osteoporotic mice by mediating the miR-34c/SATB2 axis.

Mesenchymal Stem Cells for Regenerative Medicine

In recent decades, the biomedical applications of mesenchymal stem cells (MSCs) have attracted increasing attention. MSCs are easily extracted from the bone marrow, fat, and synovium, and differentiate into various cell lineages according to the requirements of specific biomedical applications. As MSCs do not express significant histocompatibility complexes and immune stimulating molecules, they are not detected by immune surveillance and do not lead to graft rejection after transplantation. These properties make them competent biomedical candidates, especially in tissue engineering. We present a brief overview of MSC extraction methods and subsequent potential for differentiation, and a comprehensive overview of their preclinical and clinical applications in regenerative medicine, and discuss future challenges.

Fasudil may induce the differentiation of bone marrow mesenchymal stem cells into neuron‑like cells via the Wnt/β‑catenin pathway

Bone mesenchymal stem cells (MSCs) are an excellent donor graft source due to their potential for self-renewal and multidirectional differentiation. However, it is difficult to obtain high quality MSCs and to induce them to differentiate into neuron-like cells. Fasudil, a Rho kinase inhibitor, exhibits therapeutic potential in spinal cord injuries and stroke. The present study investigated the effect of fasudil on the differentiation of MSCs into neuron-like cells. MSCs were obtained from rat femur marrow, expanded in culture medium, and used at the third passage for subsequent experiments. MSCs were pre-induced with 10 ng/ml basic fibroblast growth factor (bFGF) for 24 h, which was followed by induction with fasudil. A control untreated group and a group treated with fasudil + XAV939, a Wnt/β-catenin pathway inhibitor, were also used in the present study. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunofluorescence staining were performed in order to detect neuron-specific markers, including neuron-specific enolase (NSE), nestin and neurofilament-M (NF-M). Following induction with fasudil, neuron-like cell morphology was observed. In the fasudil + XAV939 and control groups, no obvious changes in cell shape were observed. The results of RT-qPCR, western blot analysis and immunofluorescence staining indicated that expression of the neuron-specific markers NSE, nestin and NF-M was detected in the fasudil group. The differentiation of MSCs into neuron-like cells induced by fasudil was eliminated when the Wnt/β-catenin pathway was inhibited. The present study demonstrated that fasudil may induce MSCs to differentiate into neuron-like cells, however further studies are required to determine the specific mechanisms involved in the effect of fasudil on the Wnt/β-catenin pathway. In addition, further research is required to examine the functional characteristics of the induced neuron-like cells, in order to establish their suitability for clinical treatments in the future.

Bone Tissue Engineering Using Human Cells: A Comprehensive Review on Recent Trends, Current Prospects, and Recommendations

The use of proper cells for bone tissue engineering remains a major challenge worldwide. Cells play a pivotal role in the repair and regeneration of the bone tissue in vitro and in vivo. Currently, a large number of differentiated (somatic) and undifferentiated (stem) cells have been used for bone reconstruction alone or in combination with different biomaterials and constructs (e.g., scaffolds). Although the results of the cell transplantation without any supporting or adjuvant material have been very effective with regard to bone healing. Recent advances in bone scaffolding are now becoming new players affecting the osteogenic potential of cells. In the present study, we have critically reviewed all the currently used cell sources for bone reconstruction and discussed the new horizons that are opening up in the context of cell-based bone tissue engineering strategies.

Stem Cell Therapy: A Promising Therapeutic Method for Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is one type of the most devastating cerebrovascular diseases worldwide, which causes high morbidity and mortality. However, efficient treatment is still lacking. Stem cell therapy has shown good neuroprotective and neurorestorative effect in ICH and is a promising treatment. In this study, our aim was to review the therapeutic effects, strategies, related mechanisms and safety issues of various types of stem cell for ICH treatment. Numerous studies had demonstrated the therapeutic effects of diverse stem cell types in ICH. The potential mechanisms include tissue repair and replacement, neurotrophy, promotion of neurogenesis and angiogenesis, anti-apoptosis, immunoregulation and anti-inflammation and so forth. The microenvironment of the central nervous system (CNS) can also influence the effects of stem cell therapy. The detailed therapeutic strategies for ICH treatment such as cell type, the number of cells, time window, and the routes of medication delivery, varied greatly among different studies and had not been determined. Moreover, the safety issues of stem cell therapy for ICH should not be ignored. Stem cell therapy showed good therapeutic effect in ICH, making it a promising treatment. However, safety should be carefully evaluated, and more clinical trials are required before stem cell therapy can be extensively applied to clinical use.

Potential Use of Amniotic Membrane - Derived Scaffold for Cerebrospinal Fluid Applications

Scaffolds derived from decellularized tissues provide a natural microenvironment for cell culture. Embryonic cerebrospinal fluid (e-CSF) contains factors which play vital roles in the development of the nervous system. This research was aimed to survey the effect of Wistar rat e-CSF on neural differentiation of bone marrow derived mesenchymal stem cells (BM-MSCs) cultured on the human amniotic membrane (AM). BM-MSCs were collected from femurs and tibias, and were cultured in Dulbecco's Modified Eagle's Medium. The placenta was harvested from healthy women during cesarean section and AM was acellularized using EDTA and physical scrubbing. e- CSF was harvested from rat fetuses at E17. Adequate numbers of BM-MSCs were cultured on acellularized membrane, and were treated with E17 CSF for 7 days. MTT (3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) assay confirmed the survival and proliferation of BM-MSCs cultured on AM derived scaffold. Hematoxylin/eosin staining and scanning electron microscopy showed the morphological and the structural changes of BM-MSCs throughout the culture and treatment with e-CSF. The results of immunocytochemistry showed that microtubule associated protein 2 and beta-III tubulin were expressed in BM-MSCs cultured on acellular amnion scaffold and treated with e-CSF. Our results showed for the first time that the combination of acellular AM as a natural scaffold and e-CSF as a source of neurological factors could effectively improve the BM-MSCs cultivation and differentiation.

Calcium: A novel and efficient inducer of differentiation of adipose-derived stem cells into neuron-like cells

This study comparatively investigated the effectiveness of calcium and other well-known inducers such as isobutylmethylxanthine (IBMX) and insulin in differentiating human adipose-derived stem cells (ADSCs) into neuronal-like cells. ADSCs were immunophenotyped and differentiated into neuron-like cells with different combinations of calcium, IBMX, and insulin. Calcium mobilization across the membrane was determined. Differentiated cells were characterized by cell cycle profiling, staining of Nissl bodies, detecting the gene expression level of markers such as neuronal nuclear antigen (NeuN), microtubule associated protein 2 (MAP2), neuron-specific enolase (NSE), doublecortin, synapsin I, glial fibrillary acidic protein (GFAP), and myelin basic protein (MBP) by quantitative real-time polymerase chain reaction (quantitative real-time polymerase chain reaction (qRT-PCR) and protein level by the immunofluorescence technique. Treatment with Ca + IBMX + Ins induced neuronal appearance and projection of neurite-like processes in the cells, accompanied with inhibition of proliferation and halt in the cell cycle. A significantly higher expression of MBP, GFAP, NeuN, NSE, synapsin 1, doublecortin, and MAP2 was detected in differentiated cells, confirming the advantages of Ca + IBMX + Ins to the other combinations of inducers. Here, we showed an efficient protocol for neuronal differentiation of ADSCs, and calcium fostered differentiation by augmenting the number of neuron-like cells and instantaneous increase in the expression of neuronal markers.

Current and Future Trends in Adipose Stem Cell Differentiation into Neuroglia

BACKGROUND

Neurological diseases and disorders pose a challenge for treatment and rehabilitation due to the limited capacity of the nervous system to repair itself. Adipose stem cells (ASCs) are more pliable than any adult stem cells and are capable of differentiating into non-mesodermal tissues, including neurons. Transdifferentiating ASCs to specific neuronal lineage cells enables us to deliver the right type of cells required for a replacement therapy into the nervous system.

METHODS

Several methodologies are being explored and tested to differentiate ASCs to functional neurons and glia with cellular factors and chemical compounds. However, none of these processes and prototypes has been wholly successful in changing the cellular structure and functional status of ASCs to become identical to neuroglial cells. In addition, successful integration and functional competence of these cells for use in clinical applications remain problematic. Photobiomodulation or low-level laser irradiation has been successfully applied to not only improve ASC viability and proliferation but has also shown promise as a possible enhancer of ASC differentiation.

CONCLUSIONS

Studies have shown that photobiomodulation improves the use of stem cell transplantation for neurological applications. This review investigates current neuro-differentiation inducers and suitable methodologies, including photobiomodulation, utilizing ASCs for induction of differentiation into neuronal lineages.

hASC and DFAT, Multipotent Stem Cells for Regenerative Medicine: A Comparison of Their Potential Differentiation In Vitro

Adipose tissue comprises both adipose and non-adipose cells such as mesenchymal stem cells. These cells show a surface antigenic profile similar to that of bone-marrow-derived MSC. The cells derived from the dedifferentiation of mature adipocytes (DFAT) are another cell population with characteristics of stemness. The aim of this study is to provide evidence of the stemness, proliferation, and differentiation of human adipose stem cells (hASC) and DFAT obtained from human subcutaneous AT and evaluate their potential use in regenerative medicine. Cell populations were studied by histochemical and molecular biology techniques. Both hASC and DFAT were positive for MSC markers. Their proliferative capacity was similar and both populations were able to differentiate into osteogenic, chondrogenic, and adipogenic lineages. DFAT were able to accumulate lipids and their lipoprotein lipase and adiponectin gene expression were high. Alkaline phosphatase and RUNX2 gene expression were greater in hASC than in DFAT at 14 days but became similar after three weeks. Both cell populations were able to differentiate into chondrocytes, showing positive staining with Alcian Blue and gene expression of SOX9 and ACAN. In conclusion, both hASC and DFAT populations derived from AT have a high differentiation capacity and thus may have applications in regenerative medicine.

Importance and regulation of adult stem cell migration

Cell migration is an essential process throughout the life of vertebrates, beginning during embryonic development and continuing throughout adulthood. Stem cells have an inherent ability to migrate, that is as important as their capacity for self‐renewal and differentiation, enabling them to maintain tissue homoeostasis and mediate repair and regeneration. Adult stem cells reside in specific tissue niches, where they remain in a quiescent state until called upon and activated by tissue environmental signals. Cell migration is a highly regulated process that involves the integration of intrinsic signals from the niche and extrinsic factors. Studies using three‐dimensional in vitro models have revealed the astonishing plasticity of cells in terms of the migration modes employed in response to changes in the microenvironment. These same properties can, however, be subverted during the development of some pathologies such as cancer. In this review, we describe the response of adult stem cells to migratory stimuli and the mechanisms by which they sense and transduce intracellular signals involved in migratory processes. Understanding the molecular events underlying migration may help develop therapeutic strategies for regenerative medicine and to treat diseases with a cell migration component.

In Vitro Effects of Wistar Rat Prenatal and Postnatal Cerebrospinal Fluid on Neural Differentiation and P roliferation of Mesenchymal Stromal Cells Derived from Bone Marrow

Objective

Cerebrospinal fluid (CSF) plays an important role in cortical development during the fetal stages. Embryonic CSF (E-CSF) consists of numerous neurotrophic and growth factors that regulate neurogenesis, differentiation, and proliferation. Mesenchymal stem cells (MSCs) are multi-potential stem cells that can differentiate into mesenchymal and non-mesenchymal cells, including neural cells. This study evaluates the prenatal and postnatal effects of CSF on proliferation and neural differentiation of bone marrow MSCs (BM-MSCs) at gestational ages E19, E20, and the first day after birth (P1).

Materials and Methods

In this experimental study, we confirmed the mesenchymal nature of BM-MSCs according to their adherence properties and surface markers (CD44, CD73 and CD45). The multi-potential characteristics of BM- MSCs were verified by assessments of the osteogenic and adipogenic potentials of these cells. Under appropriate in vitro conditions, the BM-MSCs cultures were incubated with and without additional pre- and postnatal CSF. The MTT assay was used to quantify cellular proliferation and viability. Immunocytochemistry was used to study the expression of MAP-2 and β-III tubulin in the BM-MSCs. We used ImageJ software to measure the length of the neurites in the cultured cells.

Results

BM-MSCs differentiated into neuronal cell types when exposed to basic fibroblast growth factor (b-FGF). Viability and proliferation of the BM-MSCs conditioned with E19, E20, and P1 CSF increased compared to the control group. We observed significantly elevated neural differentiation of the BM-MSCS cultured in the CSF-supplemented medium from E19 compared to cultures conditioned with E20 and P1 CSF group.

Conclusion

The results have confirmed that E19, E20, and P1 CSF could induce proliferation and differentiation of BM-MSCs though they are age dependent factors. The presented data support a significant, conductive role of CSF components in neuronal survival, proliferation, and differentiation.

Identification of neuron-related genes for cell therapy of neurological disorders by network analysis

Bone mesenchymal stem cells (BMSCs) differentiated into neurons have been widely proposed for use in cell therapy of many neurological disorders. It is therefore important to understand the molecular mechanisms underlying this differentiation. We screened differentially expressed genes between immature neural tissues and untreated BMSCs to identify the genes responsible for neuronal differentiation from BMSCs. GSE68243 gene microarray data of rat BMSCs and GSE18860 gene microarray data of rat neurons were received from the Gene Expression Omnibus database. Transcriptome Analysis Console software showed that 1248 genes were up-regulated and 1273 were down-regulated in neurons compared with BMSCs. Gene Ontology functional enrichment, protein-protein interaction networks, functional modules, and hub genes were analyzed using DAVID, STRING 10, BiNGO tool, and Network Analyzer software, revealing that nine hub genes, Nrcam, Sema3a, Mapk8, Dlg4, Slit1, Creb1, Ntrk2, Cntn2, and Pax6, may play a pivotal role in neuronal differentiation from BMSCs. Seven genes, Dcx, Nrcam, sema3a, Cntn2, Slit1, Ephb1, and Pax6, were shown to be hub nodes within the neuronal development network, while six genes, Fgf2, Tgfβ1, Vegfa, Serpine1, Il6, and Stat1, appeared to play an important role in suppressing neuronal differentiation. However, additional studies are required to confirm these results.

Comparative study on the effect of low intensity laser and growth factors on stem cells used in experimentally-induced liver fibrosis in mice

BACKGROUND AND STUDY AIMS

The therapeutic effects of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) exposed to diode laser and/or hepatocyte growth factor (HGF) were compared in mice with experimental liver fibrosis induced by carbon tetra chloride (CCl₄).

MATERIAL AND METHODS

Animal model of liver cirrhosis was induced by intraperitoneal injection of CCl₄ in a dose of 0.4ml/kg, twice a week for 6weeks. UC-MSCs were obtained from normal full term placentas and were exposed to diode laser and/or HGF. Before treatment, UC-MSCs were labelled with red fluorescent PKH26. Fifty four male mice weighing 25-35g were randomly divided into four groups control, stem cells, CCl₄, and treated groups. After the experimental period, body and liver weights were recorded, and the liver specimens were processed for histological examination using haematoxylin and eosin, Periodic Acid-Schiff (PAS), and Masson's Trichrome staining (MT).

RESULTS

Results showed that administration of UC-MSCs stimulated by diode laser and/or HGF improved body and liver weights, reduced vascular dilatation and congestion, reduced mononuclear cellular infiltration, reduced hepatocyte vacuolation, eosinophilia, and pyknosis. Furthermore, periportal fibrosis was minimized and PAS reaction was increased. These effects were maximum when UC-MSCs were exposed to both diode laser and HGF.

CONCLUSION

UC-MSCs stimulated by both diode laser and HGF proved to be an effective therapeutic option in experimental liver fibrosis induced by CCl₄ in mice.

Therapeutic efficacy of multipotent adult progenitor cells versus mesenchymal stem cells in experimental autoimmune encephalomyelitis

AIM

In this study, we have evaluated the therapeutic efficacy of mouse multipotent adult progenitor cells (mMAPCs) in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, and compared it with mouse mesenchymal stem cells (mMSCs).

MATERIALS & METHODS

We administered PKH26-labeled mMAPC and mMSC into EAE mice and evaluated their therapeutic efficacy.

RESULTS

The mMAPC-treated mice in comparison with the mMSC group exhibited a higher suppression of EAE (p < 0.05), and a higher fold expression of neuronal genes GAP43, NG2, PDGFR, Nestin, SMI 32, BDNF and NT 3 in spinal cord (p < 0.05), suggesting a better neuroprotective and regenerative potential of mMAPC than mMSC.

CONCLUSION

MAPC may be a potential cell type, which is superior to mesenchymal stem cell for the treatment of EAE/multiple sclerosis.

Bone marrow stromal cells promote neuromotor functional recovery, via upregulation of neurotrophic factors and synapse proteins following traumatic brain injury in rats

It has previously been demonstrated that bone marrow stromal cells (BMSCs) exhibit great therapeutic potential in neuronal injuries; however, there is limited understanding of the precise underlying mechanisms that contribute to functional improvement following brain injury. The aim of the present study was to assess the effect of BMSC treatment on traumatic brain injury (TBI) in rats, and investigate if they migrate to injured areas and promote neuromotor functional recovery via upregulation of neurotrophic factors and synaptic proteins. BMSCs were cultured in vitro from female Sprague Dawley (SD) rat bone marrow and were subsequently infused into male adult SD rats via the tail vein, following induction of TBI. The results demonstrated that treatment with BMSCs significantly reduced TBI‑induced neuromotor impairment and neuronal loss, as assessed by rota rod testing, western blot analysis, modified neurological severity score and immunohistochemistry. The distribution of transplanted BMSCs was tracked by monitoring the expression of sex determining region Y (SRY) in rats. The number of cells double‑positive for SRY/neuronal nuclear antigen or SRY/glial fibrillary acidic protein was increased in the BMSC group, which demonstrated that BMSCs migrated to injured areas and differentiated into neurons and astrocytes, following TBI. Furthermore, administration of BMSCs increased expression of vascular endothelial growth factor and brain derived neurotrophic factor. Protein expression levels of synaptophysin were downregulated following TBI and this was reversed in part by treatment with BMSCs. These findings uncovered some underlying mechanisms of action of BMSCs, and may lead to their potential use as a future effective therapeutic agent for the treatment of TBI.

Effect of hyperbaric oxygen on BDNF-release and neuroprotection: Investigations with human mesenchymal stem cells and genetically modified NIH3T3 fibroblasts as putative cell therapeutics

Hyperbaric oxygen therapy (HBOT) is a noninvasive widely applied treatment that increases the oxygen pressure in tissues. In cochlear implant (CI) research, intracochlear application of neurotrophic factors (NTFs) is able to improve survival of spiral ganglion neurons (SGN) after deafness. Cell-based delivery of NTFs such as brain-derived neurotrophic factor (BDNF) may be realized by cell-coating of the surface of the CI electrode. Human mesenchymal stem cells (MSC) secrete a variety of different neurotrophic factors and may be used for the development of a biohybrid electrode in order to release endogenously-derived neuroprotective factors for the protection of residual SGN and for a guided outgrowth of dendrites in the direction of the CI electrode. HBOT could be used to influence cell behaviour after transplantation to the inner ear. The aim of this study was to investigate the effect of HBOT on the proliferation, BDNF-release and secretion of neuroprotective factors. Thus, model cells (an immortalized fibroblast cell line (NIH3T3)–native and genetically modified) and MSCs were repeatedly (3 x – 10 x) exposed to 100% oxygen at different pressures. The effects of HBO on cell proliferation were investigated in relation to normoxic and normobaric conditions (NOR). Moreover, the neuroprotective and neuroregenerative effects of HBO-treated cells were analysed by cultivation of SGN in conditioned medium. Both, the genetically modified NIH3T3/BDNF and native NIH3T3 fibroblasts, showed a highly significant increased proliferation after five days of HBOT in comparison to normoxic controls. By contrast, the number of MSCs was decreased in MSCs treated with 2.0 bar of HBO. Treating SGN cultures with supernatants of fibroblasts and MSCs significantly increased the survival rate of SGN. HBO treatment did not influence (increase / reduce) this effect. Secretome analysis showed that HBO treatment altered the protein expression pattern in MSCs.

Li+ activated nanohydroxyapatite doped with Eu3+ ions enhances proliferative activity and viability of human stem progenitor cells of adipose tissue and olfactory ensheathing cells. Further perspective of nHAP:Li+, Eu3+ application in theranostics

Spinal cord injuries (SCI) often require simultaneous regeneration of nerve tissue and bone. Hydroxyapatites are described as bioresorbable materials with proper biocompatibility and osteoconductivity, therefore its application for spinal surgery is considered. In this paper, we present repeatable method for developing nanocrystalline calcium hydroxyapatites structurally modified with Li⁺ ions (nHAP:Li⁺). Obtained biomaterials were profoundly characterized in terms of their physicochemical properties. Moreover, we have shown that nHAP:Li⁺ doped with europium (Eu³⁺) may serve as a theranostic agent, what additionally extend its potential usage for SCI treatment. The biocompatibility of nHAP:Li⁺ was determined using human olfactory ensheathing cells (hOECs) and adipose tissue-derived multipotent stromal cells (hASCs). Both population of cells are eagerly applied for cell-based therapies in SCI, mainly due to their paracrine activity. The extensive in vitro studies showed that nHAP:Li⁺ promotes the cells proliferation, viability and cell-cell interactions. Obtained results provides encouraging approach that may have potential application in regenerative medicine and that could fulfil the promise of personalized medicine - important in SCI treatment.

"Neuronal-Like Differentiation of Murine Mesenchymal Stem Cell Line: Stimulation by Juglans regia L. Oil"

Mesenchymal stem cells have been extensively used for cell-based therapies especially in neuronal diseases. Studies still continue to delineate mechanisms involved in differentiating mesenchymal stem cells into neuronal cells under experimental conditions as they have low mortality rate and hence, the number of cells available for experiments is much more limited. Culturing and differentiating of neuronal cell is more challenging as they do not undergo cell division thus, bringing them to differentiate proves to be a difficult task. Here, the aim of this study is to investigate whether Juglans regia L. (walnut oil) differentiates multipotent, C3H10T1/2 cells, a murine mesenchymal stem cell line, into neuronal cells. A simple treatment protocol induced C3H10T1/2 cells to exhibit a neuronal phenotype. With this optimal differentiation protocol, almost all cells exhibited neuronal morphology. The cell bodies extended long processes. C3H10T1/2 cells were plated and treated with walnut oil post 24 h of plating. The treatment was given (with walnut oil treated cultures with or without control cultures) at different concentrations. The cultured cells were then stained with cresyl violet acetate solution which was used to stain the Nissl substance in the cytoplasm of the induced neuronal culture. The results indicated that the C3H10T1/2 cells differentiated into neuronal-like cells with long outgrowths of axon-like structures able to take up the cresyl violet acetate stain indicating their preliminary differentiation into neuronal-like morphology with walnut oil treatment. Treating the mesenchymal stem cells can in future establish a cultured mesenchymal stem cell line as neuronal differentiating cell line model.